JPH1135523A - Purification of methyl methacrylate - Google Patents
Purification of methyl methacrylateInfo
- Publication number
- JPH1135523A JPH1135523A JP20019097A JP20019097A JPH1135523A JP H1135523 A JPH1135523 A JP H1135523A JP 20019097 A JP20019097 A JP 20019097A JP 20019097 A JP20019097 A JP 20019097A JP H1135523 A JPH1135523 A JP H1135523A
- Authority
- JP
- Japan
- Prior art keywords
- methyl methacrylate
- distillation column
- crude
- purifying
- tower
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 title claims abstract description 80
- 238000000746 purification Methods 0.000 title claims abstract description 5
- 238000000034 method Methods 0.000 claims abstract description 32
- 239000007788 liquid Substances 0.000 claims abstract description 14
- 230000002378 acidificating effect Effects 0.000 claims abstract description 12
- 239000003054 catalyst Substances 0.000 claims abstract description 12
- 238000010992 reflux Methods 0.000 claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000002253 acid Substances 0.000 claims abstract description 8
- 238000010494 dissociation reaction Methods 0.000 claims abstract description 4
- 230000005593 dissociations Effects 0.000 claims abstract description 4
- 238000004821 distillation Methods 0.000 claims description 38
- -1 ketone compound Chemical class 0.000 claims description 13
- 238000006116 polymerization reaction Methods 0.000 claims description 7
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 claims description 6
- 239000003112 inhibitor Substances 0.000 claims description 4
- NWVVVBRKAWDGAB-UHFFFAOYSA-N p-methoxyphenol Chemical compound COC1=CC=C(O)C=C1 NWVVVBRKAWDGAB-UHFFFAOYSA-N 0.000 claims description 4
- WJFKNYWRSNBZNX-UHFFFAOYSA-N 10H-phenothiazine Chemical compound C1=CC=C2NC3=CC=CC=C3SC2=C1 WJFKNYWRSNBZNX-UHFFFAOYSA-N 0.000 claims description 2
- AODAQIOEZVDQLS-UHFFFAOYSA-N 3,4-ditert-butylbenzene-1,2-diol Chemical compound CC(C)(C)C1=CC=C(O)C(O)=C1C(C)(C)C AODAQIOEZVDQLS-UHFFFAOYSA-N 0.000 claims description 2
- 229950000688 phenothiazine Drugs 0.000 claims description 2
- 239000012535 impurity Substances 0.000 abstract description 10
- 150000001875 compounds Chemical class 0.000 abstract description 7
- 230000007062 hydrolysis Effects 0.000 abstract description 4
- 238000006460 hydrolysis reaction Methods 0.000 abstract description 4
- 239000000126 substance Substances 0.000 abstract description 3
- 238000011282 treatment Methods 0.000 abstract description 2
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 39
- QSJXEFYPDANLFS-UHFFFAOYSA-N Diacetyl Chemical group CC(=O)C(C)=O QSJXEFYPDANLFS-UHFFFAOYSA-N 0.000 description 15
- STNJBCKSHOAVAJ-UHFFFAOYSA-N Methacrolein Chemical compound CC(=C)C=O STNJBCKSHOAVAJ-UHFFFAOYSA-N 0.000 description 13
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 10
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 4
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 238000007259 addition reaction Methods 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 241001550224 Apha Species 0.000 description 2
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- KQNPFQTWMSNSAP-UHFFFAOYSA-N isobutyric acid Chemical compound CC(C)C(O)=O KQNPFQTWMSNSAP-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 125000000542 sulfonic acid group Chemical group 0.000 description 2
- 239000004471 Glycine Substances 0.000 description 1
- 239000003377 acid catalyst Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 229910017464 nitrogen compound Inorganic materials 0.000 description 1
- 150000002830 nitrogen compounds Chemical class 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はメタクリル酸メチル
の精製方法に関し、さらに詳しくはケトン類化合物を含
有する粗メタクリル酸メチルを蒸留しつつ該蒸留塔還流
液を酸性触媒と接触させ高純度のメタクリル酸メチルを
得る事に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying methyl methacrylate, and more particularly to a method for purifying crude methyl methacrylate containing a ketone compound while contacting the reflux liquid of the distillation column with an acidic catalyst to obtain highly pure methacrylic acid. Related to obtaining methyl acid.
【０００２】[0002]
【従来の技術】メタクリル酸メチルは有用なプラスチッ
ク原料として重用されており、特に最大の特徴である透
明性を活かした光ファイバー、キャスト板に対しては、
原料モノマーへの要求品質も厳しくなっている。透明性
の確保には、該モノマー原料であるメタクリル酸メチル
中のケトン類化合物、特にジアセチルの濃度は１ｐｐｍ
以下とするのが好ましいと考えられている。2. Description of the Related Art Methyl methacrylate is heavily used as a useful plastic raw material.
The required quality of raw material monomers is becoming stricter. In order to ensure transparency, the concentration of ketone compounds, especially diacetyl, in the monomer raw material methyl methacrylate is 1 ppm.
It is believed that the following is preferred.
【０００３】一方、メタクリル酸メチルの製造方法も進
歩し、イソブチレン及びまたはターシャリーブチルアル
コールを酸化してメタクロレインとし、再び酸化してメ
タクリル酸とした後、メタノールと反応したり、さらに
進歩した方法ではメタクロレインとメタノールと酸素よ
り一挙にメタクリル酸メチルを製造する方法も提案され
ている。On the other hand, the method of producing methyl methacrylate has also been advanced, and isobutylene and / or tertiary butyl alcohol have been oxidized to methacrolein, re-oxidized to methacrylic acid, and then reacted with methanol, and further advanced methods have been developed. Has proposed a method for producing methyl methacrylate from methacrolein, methanol and oxygen all at once.
【０００４】いずれの方法でも、反応方法あるいは回収
精製の方法によっては、粗メタクリル酸メチルを分離し
て得た段階において、メタクロレイン、メタノールが該
粗メタクリル酸メチルに少量含有されている。加えて、
メタクリル酸メチルを製造する際の副反応により、ケト
ン類の化合物が含有される事があり、この様な場合に、
得られたメタクリル酸メチルから原料として用いられた
未反応メタクロレイン、メタノールを回収除去するとと
もに、ジアセチルその他のケトン類化合物を製品に混入
しない様にすることが重要な点である。In any method, depending on the reaction method or the method of recovery and purification, methacrolein and methanol are contained in small amounts in the crude methyl methacrylate at the stage obtained by separating the crude methyl methacrylate. in addition,
Due to side reactions during the production of methyl methacrylate, compounds of ketones may be contained, in such cases,
It is important to recover and remove unreacted methacrolein and methanol used as raw materials from the obtained methyl methacrylate and to prevent diacetyl and other ketone compounds from being mixed into the product.
【０００５】従来、粗アクリル酸、粗メタクリル酸ある
いは粗メタクリル酸メチル中の不純物を除去する方法と
しては、該不純物を特定の物質と反応させて、該アクリ
ル酸、該メタクリル酸および該メタクリル酸メチルと分
離し易い高沸化合物に変化させて塔底から抜き出し、塔
頂から高純度のアクリル酸、メタクリル酸あるいはメタ
クリル酸メチルを抜き出す方法が主流であった。Conventionally, as a method for removing impurities in crude acrylic acid, crude methacrylic acid or crude methyl methacrylate, the impurities are reacted with a specific substance to form the acrylic acid, the methacrylic acid and the methyl methacrylate. The mainstream method is to change the compound into a high-boiling compound that is easily separated from the column and withdraw from the bottom of the column, and then extract high-purity acrylic acid, methacrylic acid or methyl methacrylate from the top of the column.
【０００６】例えば、アクリル酸の精製方法としてグリ
シンを添加してアルデヒド類を除去する方法（特公昭５
０−１４号）やメタクリル酸の精製方法としてスルホン
酸基をもつ化合物と反応させて不純物を除去する方法
（特開昭５５−１２９２３９号）が提案されている。特
公昭５０−１４号には、ケトン類化合物の除去に関する
記載はなく、また、グリシンと反応させる場合、温度７
０℃で３時間加熱している為、メタクリル酸メチルに適
用すると、該メタクリル酸メチルが通常除去しきれない
水を含んでいる場合、酸との加熱により、加水分解を起
こすという不都合な結果を生じる。また、特開昭５５−
１２９２３９号記載のスルホン酸基をもつ化合物を用い
て不純物を除去をする方法も、温度７０〜１１０℃、１
分〜２時間の処理を要する為、メタクリル酸メチルに適
用すると、同様の不都合な結果となった。For example, as a method for purifying acrylic acid, a method of removing aldehydes by adding glycine (Japanese Patent Publication No.
No. 0-14) and a method for removing impurities by reacting with a compound having a sulfonic acid group (JP-A-55-129239) has been proposed as a method for purifying methacrylic acid. In Japanese Patent Publication No. 50-14, there is no description on the removal of ketone compounds.
Since it is heated at 0 ° C. for 3 hours, when applied to methyl methacrylate, if the methyl methacrylate contains water that cannot be normally removed, heating with an acid may cause an undesired result of hydrolysis. Occurs. Also, Japanese Unexamined Patent Publication No.
The method of removing impurities using a compound having a sulfonic acid group described in JP-A-129239 also has a temperature of 70 to 110 ° C.,
The same disadvantageous results were obtained when applied to methyl methacrylate because treatments of minutes to 2 hours were required.
【０００７】メタクリル酸メチルの精製方法としては、
特開昭５８−１８３６３３号に開示されたヒドラジンを
添加する方法、また、特開平８−１６９８６２号に開示
された１，２ージアミンを添加する方法が挙げられる
が、両者ともに、これらの窒素化合物の添加量が多すぎ
ると、精製メタクリル酸メチル中に未反応の窒素化合物
が混入して新たな着色原因となり、添加量が少なすぎる
と不純物との反応が不十分でメタクリル酸メチル中に不
純物の混入が起こるため、添加量を精密に制御する必要
があった。As a method for purifying methyl methacrylate,
The method of adding hydrazine disclosed in JP-A-58-183633 and the method of adding 1,2-diamine disclosed in JP-A-8-169962 can be mentioned. If the addition amount is too large, unreacted nitrogen compounds are mixed into the purified methyl methacrylate and cause a new coloring.If the addition amount is too small, the reaction with the impurities is insufficient and the impurities are mixed into the methyl methacrylate. Therefore, it was necessary to precisely control the addition amount.
【０００８】[0008]
【発明が解決しようとする課題】本発明は、メタクリル
酸メチル中の微量不純物をメタクリル酸メチルの加水分
解を起こさず、異物の混入もなく高度に除去精製する方
法を提供することを目的とする。SUMMARY OF THE INVENTION An object of the present invention is to provide a method for removing and purifying trace impurities in methyl methacrylate to a high degree without causing hydrolysis of methyl methacrylate and without introducing foreign matter. .
【０００９】[0009]
【課題を解決するための手段】本発明者らは、不純物を
反応させて高沸物としてメタクリル酸メチル等から除去
するという従来の考え方を逆転させ、不純物を低沸物と
してメタクリル酸メチル等から除去するという方法に注
目したが、該方法を用いる場合、粗メタクリル酸メチル
中にジアセチル等のケトン類化合物及びメタクロレイン
及び／またはメタノールが存在すると、ケトン類化合物
とメタクロレインまたはメタノールの付加反応が起こ
り、これらの付加物がメタクリル酸メチルに混入するこ
とが大きな問題となることを見出した。本発明者らは、
粗メタクリル酸メチルを蒸留塔で精製する際に、ジアセ
チルおよびメタノール及び／またはメタクロレインを含
む該塔頂凝縮液の少なくとも一部を該蒸留塔に還流する
に際し、該還流液と水中の酸解離指数ｐＫａ４．８以下
の酸とを接触させながら該蒸留塔に還流させることによ
り、ジアセチルの付加反応を抑制し、高純度のメタクリ
ル酸メチルが得られることを見いだし、本発明を完成す
るに至った。Means for Solving the Problems The present inventors have reversed the conventional idea of reacting impurities and removing them as high-boiling substances from methyl methacrylate and the like. Although attention was paid to the method of removing, when this method is used, if a ketone compound such as diacetyl and methacrolein and / or methanol are present in the crude methyl methacrylate, the addition reaction between the ketone compound and methacrolein or methanol is carried out. As a result, it has been found that mixing these adducts into methyl methacrylate becomes a serious problem. We have:
When the crude methyl methacrylate is purified by a distillation column, at least a part of the overhead condensate containing diacetyl and methanol and / or methacrolein is refluxed to the distillation column. By refluxing the distillation column while contacting it with an acid having a pKa of 4.8 or less, it was found that the addition reaction of diacetyl was suppressed, and it was found that high-purity methyl methacrylate was obtained, thereby completing the present invention.
【００１０】即ち、本発明は、ケトン類化合物を含有す
る粗メタクリル酸メチルを蒸留塔で精製し、高純度のメ
タクリル酸メチルを得るに際し、該粗メタクリル酸メチ
ルを蒸留し、該蒸留塔の塔頂凝縮液の少なくとも一部
を、水中の酸解離指数ｐＫａ４．８以下の酸性触媒に接
触させながら該蒸留塔に還流させ、該蒸留塔塔底から高
純度のメタクリル酸メチルを得ることを特徴とするメタ
クリル酸メチルの精製方法に関するものである。That is, according to the present invention, when crude methyl methacrylate containing a ketone compound is purified by a distillation column to obtain high-purity methyl methacrylate, the crude methyl methacrylate is distilled and the column of the distillation column is purified. At least a part of the top condensate is refluxed to the distillation column while being brought into contact with an acidic catalyst having an acid dissociation index pKa of 4.8 or less in water, and high-purity methyl methacrylate is obtained from the bottom of the distillation column. And a method for purifying methyl methacrylate.
【００１１】以下、図１を用いて本発明を具体的に説明
する。まず、原料である粗メタクリル酸メチルを供給口
１から蒸留塔Ａに供給し、塔頂からジアセチル等のケト
ン類化合物、未反応のメタクロレイン、メタノール等を
含む蒸気を抜き出す。この際、蒸気に一部含まれるメタ
クリル酸メチル等の重合を防ぐために、重合防止剤２を
添加しても良い。更に、抜き出した塔頂蒸気を塔頂冷却
器８で冷却・凝縮し、該塔頂凝縮液の少なくとも一部を
還流液３として蒸留塔Ａに還流する前に酸性触媒４と接
触させる。蒸留塔Ａに還流しない一部の塔頂凝縮液は、
塔頂凝縮液抜き出し口７から抜き出され、含有する未反
応のメタノール及びメタクロレインをメタクリル酸メチ
ル製造原料として回収する。塔頂凝縮液と酸性触媒を接
触させることにより、凝縮液中に含まれるジアセチル等
のケトン類化合物とメタクロレイン及び／またはメタノ
ールとの付加反応が抑制され、塔底液６や塔底蒸気とし
て抜き出されるメタクリル酸メチルに付加物が混入する
のを防ぐことができる。回収目的物である高純度のメタ
クリル酸メチルは、塔底液６として抜き出し、さらに次
の蒸留塔に供給して蒸留し、塔頂凝縮液として回収して
もいいし、塔底蒸気として抜き出した後、塔底蒸気冷却
器９で冷却・回収しても良い。後者の方法は、一段階で
酸性触媒等を除去でき、高純度のメタクリル酸メチルを
回収することができるので好ましい。尚、ここで、高純
度のメタクリル酸メチルとは、ＪＩＳＫ６７１６に規定
されたメタクリル酸メチルであり、かつジアセチルの含
有量が１ｐｐｍ以下のメタクリル酸メチルをいう。Hereinafter, the present invention will be described in detail with reference to FIG. First, crude methyl methacrylate, which is a raw material, is supplied to the distillation column A from the supply port 1, and a vapor containing a ketone compound such as diacetyl, unreacted methacrolein, methanol and the like is extracted from the top of the column. At this time, a polymerization inhibitor 2 may be added to prevent polymerization of methyl methacrylate or the like partially contained in the vapor. Further, the extracted overhead vapor is cooled and condensed by an overhead cooler 8, and at least a part of the overhead condensate is brought into contact with an acidic catalyst 4 before being refluxed as a reflux liquid 3 to a distillation column A. Some of the overhead condensate that does not return to the distillation column A is
The unreacted methanol and methacrolein which are withdrawn from the top condensate withdrawal port 7 are recovered as a raw material for producing methyl methacrylate. By contacting the overhead condensate with the acidic catalyst, the addition reaction of the ketone compound such as diacetyl contained in the condensate with methacrolein and / or methanol is suppressed, and the condensate is discharged as the bottom liquid 6 or the bottom vapor. It is possible to prevent adducts from being mixed into the outputted methyl methacrylate. The high-purity methyl methacrylate, which is the object of recovery, is withdrawn as a bottom liquid 6 and further supplied to the next distillation column for distillation to be collected as a condensate at the top or withdrawn as vapor at the bottom. After that, it may be cooled and collected by the tower bottom steam cooler 9. The latter method is preferable because an acidic catalyst or the like can be removed in one step, and high-purity methyl methacrylate can be recovered. Here, high-purity methyl methacrylate refers to methyl methacrylate specified in JIS K6716 and having a diacetyl content of 1 ppm or less.
【００１２】本発明で用いる粗メタクリル酸メチルと
は、ジアセチル等のケトン類化合物を含有するメタクリ
ル酸メチルをいう。該粗メタクリル酸メチルには、例え
ば、イソブチレン及びまたはターシャリーブチルアルコ
ールを酸化してメタクロレインとし、再び酸化してメタ
クリル酸とした後、メタノールと反応し、蒸留分離して
得たメタクリル酸メチルやメタクロレインとメタノール
と酸素より一挙に反応した後、蒸留分離して得たメタク
リル酸メチル等がある。The crude methyl methacrylate used in the present invention refers to methyl methacrylate containing a ketone compound such as diacetyl. The crude methyl methacrylate may be, for example, oxidized isobutylene and / or tertiary butyl alcohol to form methacrolein, oxidized again to methacrylic acid, reacted with methanol, and separated by distillation to obtain methyl methacrylate or the like. Methyl methacrylate and the like obtained by reacting methacrolein, methanol and oxygen all at once, followed by separation by distillation are available.
【００１３】本発明で用いる酸性触媒とは、液体または
該塔頂凝縮液に溶解し、水中の酸解離指数ｐＫａ４．８
以下の酸であり、これらの混合物も有用である。具体的
には硫酸、リン酸および該水溶液、メタクリル酸、酢酸
などのカルボン酸および該水溶液等が挙げられる。酸性
触媒と還流液の好ましい接触温度と接触時間は、０〜５
０℃、１分〜３０分である。The acidic catalyst used in the present invention is a solution which is dissolved in a liquid or a condensate at the top of the liquid and has an acid dissociation index pKa of 4.8 in water.
The following acids are also useful: mixtures thereof. Specific examples include sulfuric acid, phosphoric acid and the aqueous solution, carboxylic acids such as methacrylic acid and acetic acid, and the aqueous solution. The preferred contact temperature and contact time between the acidic catalyst and the reflux liquid are 0-5.
0 ° C., 1 minute to 30 minutes.
【００１４】酸性触媒の供給量は、該還流液量に対し１
０ｐｐｍから０．１ｗｔ％となる量を供給するのが好ま
しい。蒸留塔の塔底部分の温度は、メタクリル酸メチル
の重合を防止するために１３０℃以下であることが好ま
しい。本発明において、メタクリル酸メチル等の重合を
防止する為に供給される重合防止剤としては、フェノチ
アジン、ジーｔーブチルカテコール、ハイドロキノン、
４ーメトキシフェノールおよびこれらの混合物をメタク
リル酸メチル等に溶解したものを用いることができる。The supply amount of the acidic catalyst is 1 to the reflux amount.
It is preferable to supply an amount from 0 ppm to 0.1 wt%. The temperature at the bottom of the distillation column is preferably 130 ° C. or lower in order to prevent polymerization of methyl methacrylate. In the present invention, as a polymerization inhibitor supplied to prevent polymerization of methyl methacrylate and the like, phenothiazine, di-t-butylcatechol, hydroquinone,
4-Methoxyphenol and a mixture thereof dissolved in methyl methacrylate or the like can be used.
【００１５】蒸留温度は、５０℃〜１００℃であり、蒸
留圧力は加圧、大気圧あるいは減圧下で行うことがで
き、蒸留温度によって設定される。蒸留塔の形式は棚段
塔、充填塔等を用いることができる。The distillation temperature is from 50 ° C. to 100 ° C., and the distillation pressure can be increased, atmospheric or reduced pressure, and is set according to the distillation temperature. As the type of the distillation column, a tray column, a packed column, or the like can be used.
【００１６】[0016]
【発明の実施の形態】以下、実施例により本発明の方法
を具体的に説明する。％、およびｐｐｍは表示のない限
り、重量基準のものである。尚、ジアセチル含有量の定
量分析には、島津製ガスクロマトグラフ及びジーエルサ
イエンス製Ｕｃｏｎ−Ｏｉｌ充填カラムを使用した。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the method of the present invention will be described specifically with reference to examples. % And ppm are by weight unless otherwise indicated. For quantitative analysis of the diacetyl content, a gas chromatograph manufactured by Shimadzu and a Ucon-Oil packed column manufactured by GL Sciences were used.
【００１７】[0017]
【実施例１】図１に示すプロセスを用いる。内径２イン
チ、６０段の棚段塔型式の蒸留塔Ａで、塔頂より２０段
目に原料供給口１、塔頂にはブライン冷却器８を有する
減圧下で液抜きできる装置、および塔底には液面計でコ
ントロールされた減圧下で塔底蒸気を抜き出して冷却
し、凝縮液５を得る冷却器９を含む装置を有する蒸留塔
を用いて、粗メタクリル酸メチルを毎時３００ｇで供給
した。該粗メタクリル酸メチルは、メタクロレインを
０．２ｗｔ％、メタノールを０．３ｗｔ％、ケトン類化
合物としてジアセチルを０．１ｗｔ％、水を１．６ｗｔ
％含んでいた。ＰＨ２に調製した硫酸水４を毎時２５ｇ
還流液３に供給し、接触時間２分後には蒸留塔Ａに供給
した。塔頂より５ｗｔ％のハイドロキノンを含有したメ
タクリル酸メチル溶液２を毎時１０ｇで供給しながら、
還流量毎時１０００ｇ、塔頂圧２２０ｍｍＨｇで連続運
転した。還流液３と、硫酸水４の混合は２０℃にて実施
した。塔頂、塔底の各温度はそれぞれ６３℃、７０℃で
あり、塔底部より、蒸気を抜き出して冷却器９により凝
縮したメタクリル酸メチル５を毎時３００ｇで抜き出し
た。この抜き出し留分はメタクリル酸メチル９９．９ｗ
ｔ％以上でジアセチルは１ｐｐｍ以下、水分３５ｐｐｍ
を含有しており、ＡＰＨＡ５以下を得た。ＡＰＨＡと
は、色数の指標であり、ＪＩＳＫ６７１６に記された方
法で測定した。Embodiment 1 The process shown in FIG. 1 is used. A distillation column A having an inner diameter of 2 inches and a tray type of 60 stages, a raw material supply port 1 at the 20th stage from the top, a brine cooler 8 at the top, and a device capable of draining liquid under reduced pressure. The crude methyl methacrylate was supplied at a rate of 300 g / h using a distillation column having a device including a cooler 9 for extracting a condensate 5 by extracting and cooling the bottom vapor under reduced pressure controlled by a liquid level gauge. . The crude methyl methacrylate contained 0.2 wt% of methacrolein, 0.3 wt% of methanol, 0.1 wt% of diacetyl as a ketone compound, and 1.6 wt% of water.
% Included. 25 g of sulfuric acid aqueous solution 4 adjusted to PH2 per hour
The mixture was supplied to the reflux liquid 3 and supplied to the distillation column A after 2 minutes of the contact time. While supplying methyl methacrylate solution 2 containing 5 wt% of hydroquinone at 10 g / h from the top of the column,
Continuous operation was performed at a reflux rate of 1000 g / h and a top pressure of 220 mmHg. The mixing of the reflux liquid 3 and the aqueous sulfuric acid 4 was performed at 20 ° C. The temperatures at the top and bottom were 63 ° C. and 70 ° C., respectively, and steam was extracted from the bottom of the column, and methyl methacrylate 5 condensed by the cooler 9 was extracted at 300 g / h. This withdrawn fraction was 99.9w of methyl methacrylate.
Diacetyl is 1 ppm or less and water 35 ppm at t% or more.
And APHA5 or less was obtained. APHA is an index of the number of colors, and was measured by the method described in JIS K6716.
【００１８】[0018]
【実施例２】図１に示す蒸留塔Aの塔底６よりメタクリ
ル酸メチル液を抜き出し、蒸留塔Ａと同型式の蒸留塔に
供給して再度蒸留し、塔頂より留出させた塔頂凝縮液は
メタクリル酸メチル９９．９ｗｔ％以上でジアセチルは
１ｐｐｍ以下であり、ＡＰＨＡ５以下であった。蒸留塔
Ａの塔底部より蒸気を抜き出して冷却器９により凝縮す
る装置を持たない他は実施例１と同様に操作した。EXAMPLE 2 A methyl methacrylate solution was withdrawn from the bottom 6 of the distillation column A shown in FIG. 1, supplied to a distillation column of the same type as the distillation column A, distilled again, and distilled off from the top. The condensate contained 99.9% by weight or more of methyl methacrylate, 1 ppm or less of diacetyl, and APHA of 5 or less. The operation was performed in the same manner as in Example 1 except that there was no device for extracting steam from the bottom of the distillation column A and condensing it with the cooler 9.
【００１９】[0019]
【比較例１】硫酸水を供給しない他は、実施例１と同様
な条件で蒸留を行い、塔底部より蒸気として抜き出して
冷却器９にて凝縮して得たメタクリル酸メチル５は、ジ
アセチルを１９３ｐｐｍ含み、ＡＰＨＡ１０をこえてい
た。COMPARATIVE EXAMPLE 1 Distillation was carried out under the same conditions as in Example 1 except that no sulfuric acid solution was supplied. Methyl methacrylate 5 obtained by extracting as steam from the bottom of the column and condensing in a cooler 9 was obtained by converting diacetyl. It contained 193 ppm and exceeded APHA10.
【００２０】[0020]
【比較例２】硫酸（水中のｐＫａ１．９２）の代わり
に、イソ酪酸（水中のｐＫａ４．８５）を用いた他は実
施例１と同様な条件で蒸留を行い、塔底部より蒸気とし
て抜き出して冷却器９にて凝縮して得たメタクリル酸メ
チル５は、ジアセチルを１８ｐｐｍ含み、ＡＰＨＡ５を
こえていた。Comparative Example 2 Distillation was carried out under the same conditions as in Example 1 except that isobutyric acid (pKa 4.85 in water) was used in place of sulfuric acid (pKa 1.92 in water). Methyl methacrylate 5 obtained by condensation in the cooler 9 contained 18 ppm of diacetyl and exceeded APHA5.
【００２１】[0021]
【発明の効果】本発明によれば、メタクリル酸メチル中
の微量不純物をメタクリル酸メチルの加水分解を起こさ
ず、異物の混入もなく、高度に除去・精製し、高純度の
メタクリル酸メチルを得ることができる。According to the present invention, trace impurities in methyl methacrylate are highly removed and purified without causing hydrolysis of the methyl methacrylate and without contaminating foreign matters, thereby obtaining high-purity methyl methacrylate. be able to.
【図１】本発明の具体的方法の一例を示す図である。FIG. 1 is a diagram showing an example of a specific method of the present invention.
Ａ 蒸留塔 １ 原料（粗メタクリル酸メチル）供給口 ２ 重合防止剤 ３ 還流液 ４ 酸性触媒供給口 ５ 塔底凝縮液抜き出し口 ６ 塔底液抜き出し口 ７ 塔頂凝縮液抜き出し口 ８ 塔頂冷却器 ９ 塔底蒸気冷却器 A Distillation column 1 Raw material (crude methyl methacrylate) supply port 2 Polymerization inhibitor 3 Reflux 4 Acid catalyst supply port 5 Bottom condensate discharge port 6 Bottom liquid discharge port 7 Top condensate discharge port 8 Top cooler 9 Tower bottom steam cooler
Claims (5)
酸メチルを蒸留塔で精製し、高純度のメタクリル酸メチ
ルを得るに際し、該粗メタクリル酸メチルを蒸留し、該
蒸留塔の塔頂凝縮液の少なくとも一部を、水中の酸解離
指数ｐＫａ４．８以下の酸性触媒に接触させながら該蒸
留塔に還流させ、該蒸留塔塔底から高純度のメタクリル
酸メチルを得ることを特徴とするメタクリル酸メチルの
精製方法。Claims: 1. A crude methyl methacrylate containing a ketone compound is purified by a distillation column to obtain high-purity methyl methacrylate, and the crude methyl methacrylate is distilled to obtain a condensate at the top of the distillation column. Methyl methacrylate, characterized in that at least a part thereof is refluxed to the distillation column while being brought into contact with an acidic catalyst having an acid dissociation index pKa of 4.8 or less in water to obtain high-purity methyl methacrylate from the bottom of the distillation column. Purification method.
メチル蒸気を冷却器に導いて凝縮し、高純度のメタクリ
ル酸メチルを得ることを特徴とする請求項１記載のメタ
クリル酸メチルの精製方法。2. The method for purifying methyl methacrylate according to claim 1, wherein the methyl methacrylate vapor obtained from the bottom of the distillation column is led to a condenser to be condensed to obtain high-purity methyl methacrylate. .
ール、ハイドロキノン、４−メトキシフェノールから選
択される少なくとも１種の重合防止剤の存在下で、該粗
メタクリル酸メチルを蒸留塔で精製することを特徴とす
る請求項１または２記載のメタクリル酸メチルの精製方
法。3. The crude methyl methacrylate is purified by a distillation column in the presence of at least one polymerization inhibitor selected from phenothiazine, di-tert-butylcatechol, hydroquinone, and 4-methoxyphenol. The method for purifying methyl methacrylate according to claim 1 or 2.
温度が０〜５０℃である請求項１〜３のいずれかに記載
のメタクリル酸メチルの精製方法。4. The method for purifying methyl methacrylate according to claim 1, wherein the contact temperature between the condensate at the top of the distillation column and the acidic catalyst is 0 to 50 ° C.
に対し、１０ｐｐｍ〜０．１重量％であることを特徴と
する請求項１〜４のいずれかに記載のメタクリル酸メチ
ルの精製方法。5. The methyl methacrylate according to claim 1, wherein the supply amount of the acidic catalyst is 10 ppm to 0.1% by weight based on the reflux liquid of the distillation column. Purification method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20019097A JPH1135523A (en) | 1997-07-25 | 1997-07-25 | Purification of methyl methacrylate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20019097A JPH1135523A (en) | 1997-07-25 | 1997-07-25 | Purification of methyl methacrylate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1135523A true JPH1135523A (en) | 1999-02-09 |
Family
ID=16420301
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20019097A Pending JPH1135523A (en) | 1997-07-25 | 1997-07-25 | Purification of methyl methacrylate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1135523A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006036757A (en) * | 2004-06-22 | 2006-02-09 | Toray Ind Inc | Method for producing silicone monomer |
| JP2006306731A (en) * | 2005-04-26 | 2006-11-09 | Asahi Kasei Chemicals Corp | Continuous production method of unsaturated carboxylic acid ester using alkane as raw material |
| JP2007063214A (en) * | 2005-09-01 | 2007-03-15 | Asahi Kasei Chemicals Corp | A method for improving the quality of methyl methacrylate. |
| KR101278225B1 (en) * | 2011-10-12 | 2013-06-24 | 박화성 | Refining apparatus for high purity 2-hydroxyethylmethacrylate |
| KR20190013816A (en) * | 2016-05-25 | 2019-02-11 | 다우 글로벌 테크놀로지스 엘엘씨 | Process for recovering by-products from MMA |
| JP2020531673A (en) * | 2017-08-29 | 2020-11-05 | レーム・ゲーエムベーハーＲｏｅｈｍ ＧｍｂＨ | Manufacturing method of optical molding material |
-
1997
- 1997-07-25 JP JP20019097A patent/JPH1135523A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006036757A (en) * | 2004-06-22 | 2006-02-09 | Toray Ind Inc | Method for producing silicone monomer |
| JP2006306731A (en) * | 2005-04-26 | 2006-11-09 | Asahi Kasei Chemicals Corp | Continuous production method of unsaturated carboxylic acid ester using alkane as raw material |
| JP2007063214A (en) * | 2005-09-01 | 2007-03-15 | Asahi Kasei Chemicals Corp | A method for improving the quality of methyl methacrylate. |
| KR101278225B1 (en) * | 2011-10-12 | 2013-06-24 | 박화성 | Refining apparatus for high purity 2-hydroxyethylmethacrylate |
| KR20190013816A (en) * | 2016-05-25 | 2019-02-11 | 다우 글로벌 테크놀로지스 엘엘씨 | Process for recovering by-products from MMA |
| JP2019516742A (en) * | 2016-05-25 | 2019-06-20 | ダウ グローバル テクノロジーズ エルエルシー | Process for recovering by-products from MMA |
| JP2020531673A (en) * | 2017-08-29 | 2020-11-05 | レーム・ゲーエムベーハーＲｏｅｈｍ ＧｍｂＨ | Manufacturing method of optical molding material |
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